Explain the bill of exchange and its use in trade finance.

The instrument: the negotiable order — the drawer's unconditional order to the drawee to pay the payee (the three parties' design); the acceptance (the drawee's commitment — the acceptor's liability); the negotiation (the endorsement's transfer); the payment. The trade's use: the payment's term (the credit sales — the time bill); the collection route (the documentary collection: the D/P-and-D/A terms — the documents against payment/acceptance); the discounting (the banker's purchase — the liquidity's source). The law: the negotiable-instruments law's family (the Bills of Exchange Act 1882's lore; the Nepali Negotiable Instruments legislation — the Banking course's depth, LAW5802).